Field
The present specification generally relates to molds and methods for controlling mold surface quality, more specifically, to molds for shaping glass-based materials.
Technical Background
The current demand in modern electronics devices for thin, three dimensional glass-based substrates that have very high levels of surface quality has produced a need to find processes that are commercially capable of providing defect-free shaped glass-based substrates. Shaped glass forming generally refers to high temperature processes that involve heating the glass to be formed to a temperature at which it can be manipulated, and then conforming it to a mold to achieve the designed shape. Classic methods of shaping glass substrates include television tube forming, where a softened glass gob is pressed between male & female molds, and bottle forming, where glass is blown in a pair of hollowed molds.
In shaping operations, the quality of the mold surface is important for producing cosmetically acceptable glass quality that can be polished into a final glass article with minimal polishing. Metal molds can have a surface texture that reproduces onto the glass surface during the molding process. This is undesirable and it can be difficult to remove the reproduced texture from the shaped glass with polishing. Thus a need exists to control the mold surface quality to minimize or reduce the possibility of a surface texture on the mold surface that reproduces onto the shaped glass-based substrate.